[frodo2975]

Hi all, I'm currently driving a 5-speed 2002 v6 that takes a long time (~5-6 seconds) to return to idle after being revved. Also, if I floor it, then release the throttle and immediately push in the clutch, the RPM's will continue to rise for a bit before they fall.

I thought it might be a sticky/gunked up throttle cable, but it seemed fine when I turned it by hand. I also checked for gunk in the valve, but it was fine.

After doing some reading, I found this is a fairly common problem, but everyone seemed to have a different solution. Have any of you guys had this and successfully solved it?

Thanks,
-Daniel

[Triple A]

try cleaning your MAF

[rfcsoulja]

And/or try cleaning you IAC.

[frodo2975]

Thanks, I'll take a look at both as soon as the weather clears up here and let you guys know how it goes.

[Codeman]

My car does the exact same thing, i have the exact same yr, and transmission. Mine went away when I used my tuner. I also cleaned my IAC, I have not cleaned my MAF yet. Mine also tends to do it if I have the defroster, or AC on. I think it is because I have UDPs and when the AC compressor is running, it sense that it is not at a high enough psi, so it kicks the idle up. That is just another thought if you have udps. If not, try cleaning both and it should help the problem.

[mcqueen]

Check the throttle body and make sure it's not sticking after you floor it.

[frodo2975]

Well, after a long time, I've finally got around to dealing with this, since I've got some time over the summer (sorry for the wait for those of you who were sitting on the edges of your seats). I've done several things so far, but the problem hasn't gone away. Here's my list of stuff I've done:

-Checked the Throttle Body to see if it was binding, but it was fine
-Checked TPS voltage (~.98, normal)
-Cleaned MAF sensor with MAF sensor cleaner
-Checked MAF sensor voltage (within it's acceptable range, plus it responded appropriately when I revved the throttle)
-Checked DPFE sensor voltage (way too low) after I got a check engine light for the EGR valve
-Replaced DPFE sensor
-Cleaned IAC valve with carb cleaner
-Verified IAC is getting power
-Measured resistance of IAC (~11ohms, within it's normal range)
-Checked the hoses on top of the motor for vacuum leaks, but found nothing. I also sprayed carb cleaner around the engine compartment to try and find any vacuum leaks, but I realized it takes a lot of carb cleaner to get the engine to do anything, so I didn't find anything there either.

(Incidentally, I'm checking the voltages by unfolding paperclips and sticking them in the holes in the backs of connectors where the wires go in. It works good and doesn't damage the wires or connectors.)

At this point, I'm not sure what to check next. Should I start replacing parts and see what fixes it, or maybe get it professionally tuned? The only other thing I can think of is maybe the IAC valve is binding, or there's a vacuum leak somewhere I can't see. Any advice?

[v6kid]

Are you running lean? Vacuum leaks will cause you to run lean, small leak= not very lean big leak= lean problems... don't just throw parts at your car. That will usually never help with a problem this vague, and is expensive. My only guess is to try and clean the iac again. The only part i could see throwing at it would be the iac just because you will never get that thing perfectly clean.

The paperclip thing is how i do it as well... most mechanics do it that way. They also use them to jump terminals while testing.

[mp4 player]

That really sounds like an IAC or TPS problem to me.

Do you happen to have a handheld tuner?

Or know someone nearby with the same vehicle that you could swap parts with to rule them out?

[Mr. Red Pony]

SEAFOAM!!.... lol But do that too.

[Wataru]

Wait, are you saying you start the car, it idles high, you rev it, then it takes 5-6 seconds to return to a softer 750-1250RPM idle? Your car is going to idle alittle higher when you start it cold, and then idle down a touch after a few seconds.

Or are you saying it ALWAYS idles high?

[Carbon28]

it is a common problem, mines doing that today actually. Not all the time but its ususally the IAC, if you find out its the IAC and install a new one, make sure you unplug the battery and plug it back in for it to work properly.


but kinda on the subject, how do you clean the IAC, just spray some brake cleaner in there and whip around?

[frodo2975]

Hmm, I don't know if I'm running lean or not. I don't have a tuner or anything like that. Would it cost a lot of money to have it professionally tuned? I don't know anyone I could swap parts with either.

@Wataru- yeah, it idles high for a bit while it's warming up, which I'd expect, but the real problem continues even after it's completely warmed up: after I rev the motor, it takes a very long time, at least 5 seconds, to return to idle (~600-800 rpm). Lately, I've also noticed that when the car is moving, the rpm's won't drop below ~1100, but when I come to a stop, they go down to normal.

I may try going to a junkyard and see if I can buy an IAC for cheap, just to see if that's the problem.

[Gandolf]

I think it might be "normal"...

Now a days, with the computer running your car... The PCM controls engine speeds and NOT you!!!

The computer is trying to match the engine speed while moving to reduce clutch wear. You will note the high speeds when the car is moving but it falls back to the 750 RPM when you come to a full stop.

There is not much "force or power" behind the high speeds and once you shift the engine it instantly falls into that speed just fine.

If you drive it hard, those transition speeds go way up like I did a lot today... 6500 RPM with 4500 RPM shift transition hold speeds The computer is trying to make your life easy there and just let it do so. It would be nice if it was far more well explained by Ford up front...??

The computer is in Full control of your engine and your throttle pot is just another input... But it is swell!! Just learn to play with a car that is out thinking you

Now, there are "TWO" brains running your car. Your's and the PCM... Learn to work together!

[shelton gt 500]

Originally Posted by rfcsoulja And/or try cleaning you IAC.

x2!!!!

[MustangV6Man?]

Clean your MAFS.

[nukeman13]

i had this problem once.. somehow my tps sensor came unplugged. when drivin and then stopping, or reving it would take a while for the rpms to drop to normal idle.. noticed it and plugged it back in and all is fine again. i rev and rpms drop normally.

so maybe its a problem with the tps?

[Wataru]

Clean your MAFs ... I personally say never clean you MAF. Theyre fragile. If its bad, youll get a CEL. If its dirty, youll get a CEL. A reconditioned MAF is like $90 (with core returned). Fuck it up and you just threw some cash away.

Frodo - honesty, I dont see your problem lol I have an 00 thats done that since I bought it over a year ago with the stock MAF and a replaced MAF.

[nukeman13]

cant u test the MAF by starting the car then un-plugging it and if the idle changes/roughens or engine dies then its good?